Enzyme expects an adapter to be configured

Question

I created a new React application by create-react-app and I wanted to write a unit test to a component named "MessageBox" that I created in the application. This is the unit test that I wrote:

import MessageBox from "../MessageBox"; import { shallow } from 'enzyme'; import React from 'react';  test('message box', () => {    const app = {setState: jest.fn()};    const wrapper = shallow(<MessageBox app={app}/>);    wrapper.find('button').at(0).simulate('click');    expect(app.setState).toHaveBeenLastCalledWith({modalIsOpen: false}); }); 

I also added a file under 'src' folder named 'setupTests.js' with the content:

import * as enzyme from 'enzyme'; import * as Adapter from 'enzyme-adapter-react-16';  enzyme.configure({ adapter: new Adapter() }); 

I ran it by:

npm test

and I got the error:

Enzyme Internal Error: Enzyme expects an adapter to be configured, but found none. To configure an adapter, you should call Enzyme.configure({ > adapter: new Adapter() })

Do you know what can solve this problem?

Answer 1

Add it to your test case file.

import React from 'react'; import Adapter from 'enzyme-adapter-react-16'; import { shallow, configure } from 'enzyme';  configure({adapter: new Adapter()}); test('message box', ()=> {      ... })